Section 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system(a)Identification. A 5-hydroxyindole acetic acid/serotonin test system is a device intended to measure 5-hydroxyindole acetic acid/serotonin in urine. Measurements of 5-hydroxyindole acetic acid/serotonin are used in the diagnosis and treatment of carcinoid tumors of endocrine tissue.(b)Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 862.9 .52 FR 16122, May 1, 1987, as amended at 65 FR 2306 , Jan. 14, 2000